Efficiencies of chitosan nanoparticles and crab shell particles in europium uptake from aqueous solutions through biosorption: Synthesis and characterization

Adsorption of benzene and toluene onto KOH activated coconut shell based carbon treated with NH 3

“…Langmuir, Freundlich and Tempkin isotherm models were studied with their evaluated parameters presented in Table 3. The Langmuir isotherm assumes monolayer adsorption and is given as: C e (mg/L) is the adsorbate equilibrium concentration, Q e (mg/g) is the quantity of adsorbate adsorbed per unit mass of adsorbent, Q m and b are Langmuir constants which translate to the adsorption capacity and the rate of adsorption respectively (Zaini et al, 2009;Cadogan et al, 2014;Nasri et al, 2014b). A plot of Q e against C e gave curves (Fig.…”

“…The value of n relates to the favourability of adsorption process and K f represents the adsorption capacity. The slope of 1/n between 0 and 1 is a measure of the adsorption intensity or surface heterogeneity, becoming more heterogeneous as its value gets closer to zero (Tan et al, 2008b;Cadogan et al, 2014;Nasri et al, 2014b) The plot of Q e vs. C e (Fig. 6aed) gave a less fitted curve and lower R 2 value than that of Langmuir.…”

“…The lower the RMSD value the better the estimated model performs (Auta and Hameed, 2013;Cadogan et al, 2014;Nasri et al, 2014b), with Langmuir model having the lowest RMSD values. From Table 2, it is evident that PHACM-AM had higher benzene and toluene adsorption capacity (Q m ) compared to PHACM, this could be as a result of the ammonia treatment and the welldeveloped surface morphology from the SEM result.…”

Diethylenetriamine-functionalized chitosan magnetic nano-based particles for the sorption of rare earth metal ions [Nd(III), Dy(III) and Yb(III)]

“…Based on the sorbent stability, precipitation issues (above pH 6-6.5), pH variation and sorption increase with pH, further experiments were performed at initial pH 5. The sorption of Eu(III) with chitosan has been reported to involve contributions of amine and hydroxyl groups from parallel chains of the biopolymer (Cadogan et al 2014). By analogy, it is possible to suggest that trivalent cations interact with either chitosan amino groups or amino groups held on the DETA substitutes with the contribution of hydroxyl groups of the chitosan backbone.…”

Facile synthesis of chitosan derivatives and Arthrobacter sp. biomass for the removal of europium(III) ions from aqueous solution through biosorption

“…In this range it was speculated that there were critical interactions of the biosorbents with the chemical species in solution. Thus, it was deduced that under these experimental conditions, the most significant chemical (ionic) changes occurred between pH 1 and pH 3 as it was speculated that as the pH increased, the net negative surface charge increased due to a reduced protonation effect and the ionic point charge distribution contribution of the complexing ligands would tend to increasingly favor Eu(III) uptake (Cadogan et al, 2014). These ionic changes that highly influenced biosorption were attributed to the protonation of the binding sites of the biosorbents and reduction of competing H þ ions as the pH increased from 1 to 3 (Ammari, 2014).…”